Page 130 - ICJ Jan 2023

TECHNICAL PAPER COLLECTOR’S EDITION

Options for the future of cement

Karen L. Scrivener

Options for more sustainable cementitious materials are reviewed. The most
viable option involves blending Portland cement clinker with increasing levels
of supplementary cementitious materials (SCMs), but the availability of common
SCMs is low compared to the demand for cement. Calcined clays are the only other
materials that are potentially available in large enough amounts to continue the
trend of reducing clinker content in blended cements. Recently we demonstrated
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that partially replacing clinker by calcined clays combined with limestone (LC
blends) can be used to achieve blended cements with good performance at much
lower levels of clinker. Such blends can make a significant contribution to the
reduction of CO emission associated with cement production.
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Keywords: Supplementary cementitious materials; sustainability; calcined clay; limestone; CO
2
emissions.
A

s global demand for concrete follows the growth of the middle class in the

st
21 century, the concrete industry faces one defining challenge: finding ways to increase the
availability of concrete while at the same time reducing its environmental footprint. To have a
significant global impact, solutions have to be abundant, affordable, and adapted to the users in
the developing world, where most growth is expected.

CONCRETE IS AN ECO-EFFICIENT MATERIAL
Cement and concrete are essential to the infrastructure of the modern world. No other material
is able to fulfil the growing demand for building materials with such a low environmental
footprint. Its widespread availability and low cost make cement by far and away the most used
material on earth, with reinforced concrete accounting for more than half of all the manufactured
materials and products we produce. It is only because of these enormous volumes that overall
the production of cement and concrete is estimated to account for around 5-8% of man-made
CO emissions.
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The Indian Concrete Journal, July 2014, Vol. 88, Issue 7, pp. 11-21

The Indian Concrete Journal | November 2018 131